Chart drive mechanism for recorders

Claim 2

In a chart recorder instrument wherein sprockets of a sprocket mechanism connected to a synchronous motor via gearing are driven by the motor, a blank chart portion stored in folded state is pulled out by said sprockets and spread for recording of measured values thereon, and the recorded chart portion is folded again to be stored; and means define a chart supply compartment and a recorded chart receiving compartment located on opposite sides of said sprockets, the improvement comprising: an inner frame to which the sprocket mechanism, synchronous motor and gearing are secured; a movable holder housing the chart supply compartment, said chart supply compartment being disposed vertically above said chart receiving compartment and above said sprockets, said movable holder having means for guiding said chart upwardly from the chart supply compartment for recording and downwardly along the front of the instrument for display of recorded values and then into engagement with said sprockets for folding and housing said recorded chart in said chart receiving compartment, said chart receiving compartment being accessible from the front of the instrument whereby said chart drive mechanism compactly stores and displays and provides access to said chart, and means pivotally mounting said movable holder on said inner frame to permit said holder to be shifted out to the front of the instrument for access to said chart supply compartment and for loading, said holder shifting the chart supply compartment to the front of the instrument in a path over said sprockets, and shifting the guide means away from said sprockets to bring the chart out of engagement with the sprockets.

Claim 3

A chart drive mechanism as defined in claim 1 comprising a roller adjacent said sprockets and extending across the width of the chart in the vicinity of the inlet of the receiving compartment in which the recorded chart is accommodated, the part of the holder facing said roller being formed within a raised deflecting rib protruding toward the front of the instrument, said roller cooperating with said rib to cause said rib to force the chart in the vicinity of the inlet of the receiving compartment frontwardly of the instrument and thereby forcefully fold the recorded chart within said compartment.

Claim 4

A chart recorded instrument as claimed in claim 1 wherein the synchronous motor and at least a portion of the gearing are contained in a separable propulsion unit mountable in position on the inner frame of the instrument and having a disengageable coupling to said sprockets, said unit having self-contained speed reduction gears with selected reduction ratios or shifting positions combined with said synchronous motor in a unitary construction interchangeable in the mechanism with other propulsion units having different gearing arrangements.

Claim 5

A chart drive mechanism as in claim 6 wherein the propulsion unit has a case formed with an opening in the side plate on the side of the gear case, said opening being arranged to receive a locating disc provided on the inner frame, and wherein the propulsion unit has an output gear coupling to an input gear connected to said sprockets, said case opening and locating disc positioning said input and output gears for proper meshing.

Claim 6

A chart recorder instrument as claimed in claim 1 wherein the sprocket mechanism includes a transmission shaft connected to the gearing and mounted on the inner frame; a sprocket shaft parallel to the transmission shaft and mounted on the inner frame; two pairs of gears connecting said shafts together, the two pairs of connecting gears providing two speeds for the sprocket shaft related to one another in the ratio of 6:5; a sleeve mounting the two gears for the sprocket shaft, said sleeve being slidable over said sprocket shaft so that the intermeshing gears of the pairs can be shifted by sliding the sleeve, whereby to compensate for a change in the chart drive rate due to the difference between 60 Hz and 50 Hz frequencies of power sources.

Claim 7

In a chart drive mechanism fOr recorders wherein sprockets of a sprocket mechanism connected to a synchronous motor via gearing are driven by the motor, and a blank chart portion stored in folded state is pulled out and spread for recording of measured values thereon, and the recorded chart portion is folded again to be stored; the improvement comprising: means defining a chart supply compartment and a recorded chart receiving compartment located on opposite sides of said sprockets, said chart supply compartment being disposed vertically above said chart receiving compartment, and means for guiding said chart upwardly from the chart supply compartment for recording and downwardly along the front of the instrument for display of recorded values, said sprockets folding and housing said recorded chart in said chart receiving compartment, said chart receiving compartment being accessible from the front of the instrument whereby said chart drive mechanism compactly stores and displays and provides access to said chart; said compartment means comprising a movable holder housing the chart supply compartment; an inner frame; and means pivotally mounting said holder on said frame to permit said holder to be shifted out to the front of the instrument for access to said chart supply compartment and for loading, said sprockets and synchronous motor being fixed with respect to said frame and said holder shifting to the front of the instrument away from said sprockets; rollers mounted on the holder adjacent the exit of the blank-chart supply compartment so that the leading end portion of the chart can be threaded along the rollers; and a rocking roller mounted on the instrument adjacent and between the other said rollers to tension the chart portion pulled out of the compartment and spread out, said rocking roller being secured to the instrument and being arranged to engage a portion of said holder to secure the holder in operating position.

Claim 8

In a chart drive mechanism fOr recorders wherein sprockets of a sprocket mechanism connected to a synchronous motor via gearing are driven by the motor, and a blank chart portion stored in folded state is pulled out and spread for recording of measured values thereon, and the recorded chart portion is folded again to be stored; the improvement comprising: means defining a chart supply compartment and a recorded chart receiving compartment located on opposite sides of said sprockets, said chart supply compartment being disposed vertically above said chart receiving compartment, and means for guiding said chart upwardly from the chart supply compartment for recording and downwardly along the front of the instrument for display of recorded values, said sprockets folding and housing said recorded chart in said chart receiving compartment, said chart receiving compartment being accessible from the front of the instrument whereby said chart drive mechanism compactly stores and displays and provides access to said chart; said compartment means comprising a movable holder housing the chart supply compartment; an inner frame; and means pivotally mounting said holder on said frame to permit said holder to be shifted out to the front of the instrument for access to said chart supply compartment and for loading, said sprockets and synchronous motor being fixed with respect to said frame and said holder shifting to the front of the instrument away from said sprockets; rollers mounted on the holder adjacent the exit of the blank-chart supply compartment so that the leading end portion of the chart can be threaded along the rollers; and a rocking roller mounted on the instrument adjacent and between the other said rollers to tension the chart portion pulled out of the compartment and spread out, said rocking roller being secured to the instrument and being arranged to engage a portion of said holder to secure the holder in operating position.